Process of producing fermentable sugars.



4 SHEETS-SHEET 1.

Invenfor:

G. E. TOMLINSON. PROCESS 0F PRODUGING PERMENTABLB sUGARs.,

2. 1 9 1 6, 1 m J d e t D a D.. na.. l 9 1 9y 2 N. A. .J D vn L T. F N 0 I T A o I L P. P A

D. 0 5 2 3 v 1l y MMM 'G. H; TOMLINSON. .PROCESS of* PRODUGING FERMENTABLE sUGARs;

A APPLICATION FILED JAN. 29,1912. l ,082,450 Y Patented July 16, 1912.

4 SHEETS-SHEET 2.

G. H. TGMLINSON. PRQGBSS or PRODUGING FERMBNTABLB SUGARS.

APPLICATION FILED JAN. 29,1912. 1 32,456). Patented July 16, 1912.

4 SHEETS-SHEET 3.\

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G. H. TOMLINSON.

PROCESS OP PRODUING PERMBNTABLE SUGARS.

APPLICATION FILED JAN.29,1912.

1,032,450.. Patented July 16, 1912.

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GEORGE E. 'rOML1NsON, OE cHrcAeaiLLINOIs, AssIGNoR 'ro STANDARD ALCOHOL- t Y COMPANY, or NEW YORK, N. Y., A CORPORATION OE MAINE.

PROCESS OF :eiaOnUoINa` EERMENTARLE sueARs.`

incenso.

Specification of Letters' .Patent Application led January 29, 1912. Serial No. 674,166.

Patented July ie, raie.

. the following is a specification.

This invention relates to processes of producmg fermentablesugars from sawdust, wood-waste or other celluloslc raw materials by the action of heatin presence' of suitable so-called hydrolyzing agents. y Y

The primary object Vof the invention is the provision of an eiicient and economical process of this character.

For a full understanding of the invention, reference is made to the accompanying drawings illustrating one form of appara.- tus suitable for carrying it into effect.

In said drawings: Figure 1 is a vertical central section of a preferred form of apparatus, on line I-I of Fig. 2, the steam and vaporfconduits being shown in elevation; Fig. 2 is an elevation of the digester and its eduction connections, viewed from one end, the supporting columns being omitted for clearness of illustration; Fig. 3 is a plan View of the digesterwithjits connec tions; and Fig. 4 is a detail view,- on a,

larger scale, showing a preferred pipe ar-` rangement within the digester.

In the drawings," 1 represents the sheet-v metal body of the digester internally lined with acid-resisting brick 2, set in a suitable cement inert to the hydrolyzing agent used.

.For use with sulfuric or sulfurous acid a of, .andthe condensation so limited that thel mass is maintained throughout the entire operation in an open, permeable and absorp` tive state, as more fully pointedy out in my copending application, Ser. No. 664,373, filed Dec. 7, 1911.

The digester is providedwith amanhole 3 for the introduction and discharge of the material, and with a blow-011:' cock 4, which in one position Of the digester maybe coupled with the blow-off pipe 5. The digester is mounted on hollow trunnions 6, 7 and is adapted for rotation by means of a wor- Im gear 8. 'l

In its preferred embodiment, my process involves the introduction of steam and a hydrolyzing agent into the digester, and the withdrawal of the vapors therefrom, without interrupting its movement of rotation. Connections permitting this mode of operation comprise, in the form of apparatus f illustrated, a fixed pipe'9`extending through the hollow trunnion 6, axially disposed within the digester, and perforated as indicated atl() for the admission of'steam tothe ini terior of the charge. This steam-pipe is provided with a check-valve 11, and is connected with a source 'Of steam controlled by a valve 13.

In practice, a plurality of similar ldigesters are usually employed, and means are preferably provided' whereby any digester -of the series may be blown oi into other digesters which maybe in condition to receive the steam or vapors therefrom. For

Ythis purpose,I provide a conduit lll,l having similar connections toy each4 digester of the series. As illustrated, such connections comprise a pipe 15, communicating with the steam-inlet pipe 9 at a point between the check-valve l1 and the control valve 13, by meansof the pipe 16 fitted with a Valve 17; and likewise communicating through pipe 18, having a valve 19, with the vaporeduction pipe 20. This pipe 20 enters the digester through the hollow trunnion 7, and is in alinementwith the steam-inlet pipe 9 and is attached thereto Vby a T connection 21, communication between the pipes 9 and 2O being interrupted by a blank flange 22.

23 is av curved vapor-eduction pipe, wl1ich is carried by the steam-inlet pipe 9 and by the -vapor-eduction pipe 20, communicating with the latter through the T 21, but sealed from the pipe 9 by a blank flange 2 4 in the T connection 25. The' pipe 23 arches upwardly into the vaplor space of the digester, and is perforated t v, A sillustrated in Fig. 1, and indicated by ddtted lines in Fig. 2, the pipe 23 extendsby pipe 12,'

erein as indicated a't'26.

upwardlyfrom'the axis of the digester at an angle of approximately 45 from 'the vertical. The result of this arrangement is that when.the digester is rotated in the direction indicated by the arrow in Fig. 2, thepipe' 23 lies substantially at a right angle tothe inclined surface of the charge. It

therefore not only extends to the maximum degree into the vapor space of the digester,v

but it is subject to the minimum strain due to the weight and pressure of the'charge,

` The pipe 20 communicates at a point outside the digester with a vapor-pipe 27 leading to a suitable condenser 28 for volatile products. In the pipe 27 I place a valve 29, and around this valve I arrange a vapor bypass 30, provided with a pop-valve 32, which when properly set will-serve to keep the pressure uniform, and thereby to avoid excessive temperatures.

The hydrolyzing agent is `introduced into the digester through a valved pipe 33, which lies within the vapor-eduction pipes 20 and I 23, and terminates in a spray-nozzle 34, lo-

cated in the vapor space of the digester and' directed toward the surface of the charge therein.

An illustrative procedure, when my `process is applied to the, treatment of resinous woods, is as follows: The digester is charged, with moist sawdust or wood-waste to such extent that the steam-inlet pipe- 9 is covered, while the perforated portion of the arched eduction-pipe 23 is exposed.' The digester is' then `closed and set 1n rotation,y

and steam is admitted under suitable pressure to the interior of the charge through the axial, perforated pipe 9, until the wood is brought to a temperature proper for the,

distillation of turpentine orsimilar volatile products, but below that at which any material decomposition of cellulose occurs, such decomposition at high temperatures resulting, as is well known, in the production of considerable quantities of acetic acidsv and tarry and phenolic bodies. For this purpose, a temperature not exceeding that of steam under a pressure of twenty to thirty pounds will usually suice, and lower pressures may be used if desired. The valve 29 being opened, the turpentine and steam will iiow through the perforations 26 into the pipe system 23, 20, 27, and thence to the condenser 28 where the turpentine and any accompanying volatile products will be recovered. Thls distillation is until the elimination ofthe' turpentine is substantially complete. The steam-supply is then cut off, the eduction-valve 29 closed, and the hydrolyzing agent admitted into the digester through the spray-nozzle 34.

In the preferred practice of the invention, the hydrolyzing agent is supplied at a t'emperature materially below that of the wood,A

which has, by the treatment above described,

55 -been brought to` a temperature' above the continued vaporizing point of water. The moisture contained in the original sawdust, or intro'- duced with the steam, exists at this -temperature largely or wholly as vapor, which permeates theA Wood and fills the pores and inlterstices thereof; and the immediate effect of the introduction of the cold hydrolyzing agent is to bring about a partial or complete condensation of this vapor, with the result that a partial vacuum is formed within the digester, the effect'being to secure a deeper, more intimate, and 'more rapid penetration of the hydrolyzing agent into the substance of the particle to be converted. Furthermore, the conditions render it possible to secure a very perfect admixture of'the hydrolyzing agent'with the material to be converted, since the hydrolyzing agent is discharged from above upon the surface of the sawdust, which, under the continued rotation of the digester, is caused to flow or fall in a continuous stream past the s ray-nozzle 34. By proceeding as above, I have found it possible to secure a highly effectivel and intimate distribution fof the hydrolyzing agent through the sawdust, and I have further found that this intimate distribution results in a material increase in the percentage of fermentable sugars yielded by the subsequent digestion.

Preferably the hydrolyzing agent is introduced as an aqueous solutlon, as for example a solution of sulfuric, sulfurous or Y .preferably sufficient to bring the acid concentration, based upon the total moisturecontent of the material, to 0.2-0.5per cent. When an acid solution is introduced as above described at a temperature materially below that of the wood-waste, it is possible that a` materially-increased percentage of liquid may be supplied to the charge without saturating it to the limit of its absorptive capacity, byreasonof the deeper penetration obtained. It is regarded as important that the total liquid-content of the charge, after the introduction of the hydrolyzing agent, should be less than is required for its complete, saturation, in order that the mass may retain its open, permeable and absorptive condition throughout the subsequent steaming for the production of fermentable tained, the hydrolyzing agent, either as gas or liquid,` being vforced into the digester at sugars; and a prlmary purpose of the decharge, steam is again admitted through the l pipe 9 and the temperature maintained at a degree proper for the conversion, 'for a suitable time. As a general rule, in the case of sawdust from coniferous woods, a temperature of 275 to 325 F., maintained for thirty to forty-five minutes, will suiice. The` steam is then blown off and the digested material is leached for the extraction of fermentable sugars. The conditions of the process are such that the digested material is relatively hard, granular and non-absorptive, which qualities permit the leaching to be quickly effected in diffusion apparatus of standard type. The resulting solution may thereafter be fermented and distilled for the recovery of alcohol in accordance with known methods. i

In case a plurality of digesters are operated, it is preferred to blow olf the steam either at the close of the digestion or following the distillation step, into another digester which has been freshly charged. This is accomplished by openinv the valvek 19, when the steam, together with any volatile matters carried thereby, will pass throughl the pipes 18 and 15, and conduit 14, flowing thence to other digesters through the inletpipe 16 thereof. If desired a portion of the vapors may be discharged into the air through the blow-.olf cock 4 and pipe 5, in order to economize time or to avoid the gradual accumulation, in successively-operated digesters, of such volatile products as i may be objectionable either in the digestion or 1n the subsequent fermentation.

In case non-resinous woods are treated the step of distillation is of course omitted but the operation may be otherwise essentially as above described. The preliminary steaming of the wood is advantageous in any case, in conjunction with the supply of the hydrolyzing agent at a lower temperature, as

` assuring the increased .penetration above described.

Itis to be understood that the conditions above recited relating to the nature and proportion of hydrolyzing agent used, the temperatures and pressures employed, and the time of the operatiomare to be regarded as illutrative, and may be varied within rather wide limits, depending upon the character of the raw material, the scale of operations, and other factors.^ Furthermore, the conditions, as regards concentration and quantity of acid, time and temperature of heating, are to a considerable degree convertible factors, and may therefore be varied with mutual correlation Within comparatively wide'limits.

The apparatus herein referred to is described in my copending application Ser. No. 674,165, led January 29, 1912.

I claim:

1. In a process of producing fermentable sugars from ligno-cellulose or other cellulosic raw material, the step which consists in heating the moist material to a temperature suiiicient to vaporize a substantial proportion of the contained moisture, and then bringing a hydrolyzing agent into contact therewith.

2. In a process of producing fermentable sugars from ligno-cellulose or other cellulosic raw materials, the steps which consist in heating the moist material to a temperature suiiicient to vaporize a substantial proportion of the contained moisture, and then bringing a hydrolyzing agent at a lower temperature into contact therewith.

3. In a process of producing fermentable sugars from ligno-cellulose or other cellulosic raw -materials, the steps which consist in heating the moist material to a temperature suiticientto vaporize a substantial proportion of the contained moisture, and then mixing therewith a liquid hydrolyzing agent at a lower temperature.

4. In a process of producing fermentable sugars from ligno-cellulose or other celluloslc raw materials, the steps which consist in heating the material by direct action of Steam to at least 2120 F., and then bringing a hydrolyzing agent at a lower temperature into contact therewith.

5. In a process of producing fermentable sugars from ligno-cellulose or other cellulosic raw materials, the ste s which consist in heating the material whi e in a state of motion by direct action of steam to atleast 212 F., and then spraying upon the surface of the moving mass a liquid hydrolyzing agent at a` lower temperature.

6. In a process of roducing fermentable sugars from ligno-cel ulose or other cellulosic raw materials, the steps which consist in preheating the charge, and then bringing a.

ydrolyzing agent at a lower temperature into contact therewith.

7. In a process of roducing fermentable sugars from ligno-cel ulose or other cellulosic rawv materials, the steps which consist in tilling the volatile products in a current of steam, then applying ,a hydrolyzing agent turpentine and lsimilar volatile products and fermentable sugars, which consists in distlling the' volatile products in a currentof steam, then applying a hydrolyzing agent -and digesting the charge until fermentablc sugars'are formed, the chargeibeing mainy tainedA in'motion during the steps of distillation and digest-ion.

lL'The process of treating comminuted coniferous Woods for the manufacture ofA turpentine and similar volatile products and fermentable sugars, which consists in distilling the volatile products in a current of steam,then distributing a liquid hydrolyzing agent, at a temperature belowv that of the heated wood, upon the surface thereof, and digesting the charge until fermentable sugars are formed, the charge being maintained in motionsubstantially throughout the operation.

'12. The process 'of producing fermentable'- sugars from ligno-cellulose or other cellulosic'raw materials, which consists inl heating' the moist material to a temperature suflicient' to vaporize a substantial proportion of the contained moisture, bringing a hydrolyzing agent at a lower temperature into Contact therewith, and digesting the mass by direct action of steam until fermentable sugars are formed, the mass being maintainedthrough# out `the treatment in an A unsaturated and `,absorptive condition.

13. The process of producing fermentable vsugars from ligne-cel ulose or other cellulosic raw materials, which consists in heating' the moist material to a temperature sufficient `to vaporize a substantial proportion of the contained moisture, mixing therewith a liquid hydrolyzing agent at a lower temperature in proportion insufficient to eect satu-- ration of the mass, and digesting the resulting mass by direct action of steam unt-il fermcntablesugars are formed, the mass being maintained throughout the treatment in'an unsaturated and absorptive condition. In testimony whereof I aiiix mysignature in presence of two witnesses.

GEORGE H. TOMLINSON. Witnesses f l C. L. EFFINGER, J. E. MAYO. 

